The disclosure of Japanese Patent Application No. HEI 10-280024 filed on Oct. 1, 1998 including the specification, drawings and abstract is incorporated herein by reference.
1. Field of the Invention
This invention relates to a vehicle seat housing an airbag device, and particularly to a vehicle seat housing an airbag device on a side portion of a seat back frame.
2. Description of the Related Art
Conventionally, Japanese Laid-Open Patent Application No. HEI 10-76904 is known as an example of a vehicle seat housing an air bag device on a side portion of a seat back frame.
As shown in FIG. 10, in a vehicle seat housing this type of airbag device, a pad 102 of a seat back 100 receives expansion pressure of an airbag pouch body 104. A cut-in groove portion 106 is provided as a pad expansion commencement point setting portion which becomes the activation point portion at which the pad 102 begins expanding and breaking. This cut-in groove portion 106 is disposed at a position that is offset from an airbag pouch body expansion direction in which the airbag pouch body 104 directly contacts a seat interior surface of the pad 102. Furthermore, this cut-in groove portion 106 is disposed on the side of a line 112 connecting the top portion of a side support 100A and an axis of an inflator 110 within an airbag device 108 that is opposite the side on which a center of the seat is located.
However, in a vehicle seat housing this type of airbag device, if the pad 102 is formed to be soft, in order to improve sitting comfort, when the airbag pouch body 104 is expanded and developed, the pad 102 can easily be expanded into a balloon state. As a result, energy is lost with respect to development capability of the airbag pouch body 104 during the process until the airbag pouch body 104 breaks the pad 102 and a surface covering 114. Therefore, expansion capability of the airbag pouch body 104 is considered to be unstable.
An object of this invention is to obtain a vehicle seat housing an airbag device which can control energy loss due to deformation of a seat pad during expansion.
In a first embodiment of this invention, a vehicle seat housing an airbag, device which is fixed to a door side portion of a seat back side frame in a concave portion of a seat pad which is open to a rear side of the vehicle and covered by a seat surface covering has a guide means which is disposed at an inward side of the front surface of the scat pad. The guide means is positioned on a side of a plane connecting an axis of an inflator of the airbag device and a breakage sewn portion of the seat surface covering that is closer to a center of the seat, at an airbag pouch body expansion area. The guide means is harder than a main portion of the seat pad. The guide means is deformed by expansion pressure of the airbag pouch body and guides an airbag pouch body in a predetermined direction.
Therefore, by the guide means which is additionally provided on the seat pad, with respect to the initial expansion of the airbag pouch body, the expansion direction of the airbag pouch body is deflected by the rigid effect and the expansion can be realized that aims at a breakage sewn portion of the seat surface covering. As a result, energy loss due to deformation of a seat pad during an airbag pouch body expansion can be controlled, pressure can be focused at a breakage sewn portion, and this can be instantly broken, so expansion speed of the airbag pouch body can be improved. In addition, along with the expansion of the airbag pouch body, the guide means is deformed by expansion pressure of the airbag pouch body and guides the airbag pouch body in a predetermined direction, so completion time of the airbag pouch body expansion can be speeded up.
The guide means can be structured by resin press felt. By using resin press felt for the guide means, manufacturing can be easily performed and cost can be lower.
The guide means can be structured by a harder pad than a main portion of the [seat] pad. By using a hard pad for a guide means, manufacturing can be easily performed and cost can be lower.
The guide means extends to an inward position in a seat width direction which overlaps a front end portion of the seat back side frame by a predetermined amount. By so doing, the airbag pouch body to be expanded cannot be easily inserted between the front end portion of the seat back side frame and the seat pad, so the expansion direction of the airbag pouch body can be effectively adjusted.
In a second embodiment of the invention, a vehicle seat housing an airbag device which is fixed to a door side portion of a seat back side frame in a concave portion of a seat pad which is open to a rear side of the vehicle and covered by a seat surface covering has a guide means which is disposed on the seat back side frame. The guide means is positioned on a side of a plane connecting an axis of an inflator of the airbag device and a breakage sewn portion of the seat surface covering that is closer to a center of the seat, at an airbag pouch body expansion area. The guide means is harder than a main portion of the seat pad. The guide means is deformed by expansion pressure of the airbag pouch body and guides an airbag pouch body in a predetermined direction.
Therefore, by the guide means which is provided on the seat back side frame, with respect to the initial expansion of the airbag pouch body, the expansion direction of tile airbag pouch body is deflected by the rigid effect and the expansion can be realized that aims at a breakage sewn portion of the seat surface covering. As a result, energy loss due to deformation of a seat pad during an airbag pouch body expansion can be controlled, pressure can be focused at a breakage sewn portion, and this can be instantly broken, so expansion speed of the airbag pouch body can be improved. In addition, along with the expansion of the airbag pouch body, the guide means is deformed by expansion pressure of the airbag pouch body and guides the airbag pouch body in a predetermined direction, so completion time of the airbag pouch body expansion can be speeded up.
The guide means can be structured by a deformable plate, one end portion of which is fixed to a front end portion of a seat back frame.
Furthermore, the guide means can be structured by a deformable plate, one end portion of which is fixed to a side surface portion of the seat back frame.
By so doing, the expansion direction of the airbag pouch body can be easily adjusted by the material and plate thickness of the plate.
In a third embodiment of this invention, a vehicle seat housing an airbag device which is fixed to a door side portion of a seat back side frame in a concave portion of a seat pad which is open to a rear side of the vehicle and covered by a seat surface covering has a hard pad portion which forms part of the seat pad. The hard pad portion is positioned on a side of a plane connecting an axis of an inflator of the airbag device and a breakage sewn portion of the seat surface covering that is closer to the center of the seat, at an airbag pouch body expansion area. The hard pad portion is harder than a main portion of the pad.
Therefore, by a guide means which is provided on the seat pad, with respect to the initial expansion of the airbag pouch body, the expansion direction of the airbag pouch body is deflected by the rigid effect and expansion can be realized that is aimed at a breakage sewn portion of the seat surface covering. As a result, energy loss due to deformation of the seat pad during airbag pouch body expansion can be prevented, pressure can be focused on a breakage sewn portion, and this can be instantly broken, so expansion speed of the airbag pouch body can be improved. In addition, along with the expansion of the airbag pouch body, the hard pad portion positioned at the airbag pouch body expansion area is deformed by expansion pressure of the airbag pouch body and guides the airbag pouch body in a predetermined direction, so completion time of the airbag pouch body expansion can be speeded up.
In the first through third embodiments, it is possible to dispose a supplemental guide means that is deformable by expansion pressure of the airbag pouch body, and which is harder than a main portion of the pad, on an inward surface facing a door side portion of the airbag device in the seat pad. By so doing, the expansion direction of the airbag pouch body can be effectively adjusted by the guide means and the supplemental guide means. When a caseless side airbag device is used, because the airbag device itself is soft, there is a concern that seat rigidness is insufficient when it is externally touched if the seat side portion of the seat pad is thin. However, rigidness is not lost because the supplemental guide means is set.
The supplemental guide means extends to a rear position which overlaps a protector, which is fixed to a door side portion of the seat back side frame and maintains an expansion space of the airbag pouch body during a side collision, by a predetermined amount.
Therefore, interference between a seat pad and an edge of the protector can be prevented by the supplemental guide means, and damage of the pad by the edge of the protector can be prevented.